Research On The Process Of Treating Refractory Gold Ores Containing Antimony With Bath Smelting Technology

Abstract:The traditional treatment methods of refractory gold ores are as following pretreatment, cyanide leaching, and replacement by zinc. Due to the complexity of refractory gold ores, the traditional methods are facing a seize of problems, such as, environmental pollutions, low cyanide leaching, high cost and so on. A new process of treating refractory gold ores was put forward in this work. It had advantage over production efficiency. The new technology is matte smelting in order to recovery gold, oxidizing smelting to enrich gold.The refractory gold ores containing antimony were used as raw material in this study. The gold was recovered because precious metals can be enriched in matte. First thermodynamic of reaction in bath smelting process were analyzed.Second, the reactions that could occur during the melting process were discussed. Exploratory experiments about slag type, ventilation conditions, and experimental program were conducted. The results showed that slag was FeO-CaO-SiO2, ventilation kind was oxygen, ventilation depth was boundary between slag and matte, experimental program was two-step melting which was matte smelting and oxidizing smelting.A comprehensive study of two-step smelting was conducted in this paper. The effects of FeO/SiO2, CaO/SiO2, smelting temperature, holding time, and additives were studied in matte smelting process, the effects of FeO/SiO2, CaO/SiO2, smelting temperature, ventilation time, ventilation rate, holding time in oxidizing smelting process. The distribution of noble metal elements and other elements in slag and matte were researched. The experience of returning oxidizing smelting slag to matte smelting was carried out to study gold recovery effectThe research results showed that the appropriate smelting conditions in matte smelting were:FeO/SiO21.1, CaO/SiO20.4, experimental temperature1200℃, holding time30min. Under these conditions, the recovery of Au was98.47%, the recovery of Ag was80.64%, the content of Au in slag was0.75g/t. In the oxidizing smelting experiments, the optimum conditions were:FeO/SiO21.5, CaO/SiO20.3, ventilation time 17min, ventilation rate0.6L/min, experimental temperature1250℃, holding time30min. The recovery of Au and Ag were79%and55%, respectively. The content of Au in matte and slag were385g/t and22g/t, the content of Ag in matte and slag are950g/t and160g/t. The content of Au in oxidizing slag can be reduced to1g/t or less after returning it to matte smelting. Therefore, the gold in oxidizing smelting slag can be recovered effectivelyThe results shows:recovering gold from refractory gold ores by matte smelting is a practical way. The recovery and enrichment of gold have been realized by the process of matte smelting and oxidizing smelting. This process has has high recovery, high production efficiency, and provides a new approach for refractory gold ores.